Disc brake for a utility vehicle

Abstract

A disc brake for a commercial vehicle, comprising a brake caliper (1) designed as a sliding caliper and extending over a brake disc (12), two brake pads (3) arranged therein, movable in opposite directions towards the brake disc (12), each having a pad carrier plate (4) and a friction lining (5) attached thereto, each being preloaded by means of a pad retaining spring (10) against which a pad retaining bracket (11) held on the brake caliper (1) and spanning a mounting opening of the brake caliper (1) is supported, in a pad recess of a vehicle-side brake carrier (2) limited in the direction of rotation of the brake disc (12) by brake carrier horns (9), and with a return mechanism by which the brake pads (3) can be returned after a braking-induced displacement and release of the brake, wherein the return mechanism engages the opposing brake pads (3),The device has spring-loaded spreading elements (6) that act in the same way opposite to the respective clamping direction, wherein two V-shaped spreading elements (6) are provided which are supported or attached to the pad retaining bracket (11) in the connection area (13) of their respective spring legs (7), wherein the spring legs (7) of each spreading element (6) are held with their ends (15) on the opposing brake pads (3), is designed such that each end (15) is inserted into a bore of the pad retaining spring (10) or into a bore of the pad carrier plate (4).

Description

[0001] The invention relates to a disc brake for a commercial vehicle according to the preamble of claim 1.

[0002] When in operation, i.e. during braking, the brake pads of such a sliding caliper disc brake are applied by an application device, whereby first the application-side brake pad is pressed against the brake disc and then the opposite, reaction-side brake pad is pressed against the brake disc.

[0003] The action-side brake pad is pressed against the brake disc via the brake piston of the application device, while in order to press the reaction-side brake pad, the brake caliper, designed as a sliding caliper, is moved against the application direction of the action-side brake pad.

[0004] After the brake is released, the brake calliper of the well-known disc brake remains in this latter position, in which the brake pads, or at least the reaction side, are in contact with the brake disc without pressure but with a frictional contact.

[0005] The resulting residual grinding torques during driving lead to increased fuel consumption of the vehicle as well as a reduction in the service life of both the brake disc and the brake pads.

[0006] While the vehicle is in operation, the brake pads may become slightly loose due to the wobbling of the brake disc, as well as vibrations and lateral acceleration when cornering, these effects are not sufficient to effectively prevent the aforementioned grinding.

[0007] In WO 2016 / 202778 A1 and DE 10 2016 124310 A1, it is proposed to solve this problem by providing a disc brake with resilient spreading elements forming a return device, by means of which the brake pads are actively returned after the end of braking, i.e., brought out of the area of ​​action of the vehicle-side brake disc.

[0008] Each brake pad is assigned a spreading element, each with two spring arms that engage with the respective pad carrier plate.

[0009] These expansion elements are attached to a retaining bracket that extends essentially parallel to the brake disc, which in turn is attached to a vehicle-mounted brake carrier. This design prevents the buildup of residual drag torque, which leads to increased brake pad wear.

[0010] Although this reset device has proven itself in practice, it can only be implemented with a relatively high manufacturing effort, which contradicts the constant demand for cost minimization.

[0011] From DE 4301621 A, a disc brake with a stationary brake carrier is known, which has two lining shafts for receiving the brake pads, wherein each lining shaft is delimited in both circumferential directions of the brake disc by brake carrier horns, on which a lining carrier plate of the respective brake pad carrying a friction lining is slidably supported in the application direction.

[0012] To reset the brake pads, a spring arrangement is provided which acts axially on the brake pads in the brake release direction and which supports the adjustment of the clearance between the brake pads and the brake disc after the brake is released.

[0013] This spring arrangement has two spring spreading elements, each with two spring arms, which rest resiliently on the lining carrier plate above the friction lining, whereby the respective spreading element is fixed to a stationary component, for example the brake carrier.

[0014] US 2014 / 033 9026 A1 describes an expansion element comprising a locking arm connecting the expansion element to a brake pad, a retraction arm, and a pretensioning device arranged between the locking arm and the retraction arm. The pretensioning device comprises spiral spring loops that store energy during a braking operation and retract the brake pad after the braking is released.

[0015] Deviating from the type, this design does not concern a sliding caliper brake, but a floating caliper brake, which is used in a passenger vehicle but is not suitable for a commercial vehicle.

[0016] DE 10 2016 004516 A1 discloses a disc brake with a return device which has resilient spreading elements acting in the same way as the respective application device, according to the type.

[0017] In one design variant, these spreading elements consist of separate spring legs, each of which is attached at one end to the associated brake pad and at the other end to the spoke of a pad retaining bracket, wrapping around it.

[0018] In another variant, the spring legs of each expansion element are connected to each other by a helically wound area that wraps around a spoke of the pad retaining bracket.

[0019] Disc brakes deviating from this type are known from US 4 491 204 A and JP S57 179435 A.

[0020] The invention is based on the object of further developing a disc brake of the generic type in such a way that its reset device is of simpler construction and can thus be manufactured more cost-effectively and its operational reliability is improved.

[0021] This object is achieved by a disc brake having the features of claim 1.

[0022] Compared to a prior art disc brake, the design according to the invention offers significant advantages. These arise, among other things, from the extremely simple implementation of the invention, since only two, preferably one-piece, spreading elements are provided. After the brake is released, the brake pads are moved by the spring pressure of the spring legs, which are tensioned during braking, into a position where they no longer rest against the brake disc.

[0023] In principle, the expansion elements can be formed from spring wire, which not only makes them easier to manufacture but also improves their service life. This is particularly important because disc brakes, as safety-critical components, are subject to special requirements.

[0024] The V-shaped design of each expansion element allows for its use with a variety of brake pads, each of which has identically positioned mounting points for the ends of the spring legs. This allows for prefabrication of the expansion elements, significantly reducing their procurement costs.

[0025] The V-shaped design of the expansion elements is to be seen in the broadest sense, with each expansion element having spring legs which, at least in some areas, run diagonally to one another towards a common connecting area.

[0026] At least one of the spring legs is designed in such a way that it is supported on an associated pad retaining spring of the corresponding brake pad in order to prevent tipping towards the brake disc, with each connecting area resting on the underside of the pad retaining bracket.

[0027] An alternative design variant provides that each expansion element is fastened to the retaining bracket in the connection area of ​​the spring legs, for example by means of clamping means.

[0028] Since the expansion elements rise in the direction facing each other, the connection areas are prevented from rising up when the brake pads are applied by their contact with or connection to the pad retaining bracket.

[0029] According to a further idea of ​​the invention, the expansion elements are designed and mounted asymmetrically so that in the event of wear of the brake pads and the resulting displacement of the connecting areas of the expansion elements, they can slide past each other under the pad retaining bracket.

[0030] The ends of the spring legs can be fixed to the lining carrier plates in different ways, according to the invention by inserting these ends into holes in the lining carrier plate or the lining retaining spring.

[0031] Further advantageous embodiments of the invention are characterized in the subclaims.

[0032] Embodiments of the invention are described below with reference to the accompanying drawings.

[0033] They show: Fig. 1 a disc brake according to the prior art in a perspective top view Fig. 2 and 3 a partial section of the disc brake according to the invention in a perspective view Fig. 4 to 8 an embodiment of the invention, each also in a perspective top view Fig. 9 a detail of the disc brake in a diagrammatic representation Fig. 10 an alternative embodiment of the invention in the mounted position of the spreading elements Fig. 11 a further embodiment of the spreading elements shown as a detail.

[0034] In the Fig. 1 A disc brake for a commercial vehicle according to the prior art is shown. This disc brake has a brake caliper 1, which is slidably mounted on a brake carrier 2 that can be attached to the vehicle, and in which two spaced-apart brake pads 3 are mounted for opposing movement.

[0035] Each brake pad 3 has a pad carrier plate 4 and a friction pad 5 fastened thereon, wherein a pad retaining spring 10 is fastened to each pad carrier plate 4, which is supported on a pad retaining bracket 11 which engages over a mounting opening of the brake calliper 1 and by means of which the brake pads 3 are held under pretension in pad shafts of the brake carrier 2, which are laterally delimited by brake carrier horns 9.

[0036] In order to return the brake pads 3 to their non-functional position after a braking operation, a return device is provided which is formed from two spreading elements 6 which engage the pad carrier plates 4 by means of spring legs 7 in the areas adjacent to the brake carrier horns 9.

[0037] The spreading elements 6 are, on the other hand, attached to a retaining bracket 8 as a further component of the return device, which is inserted at both ends into a brake carrier horn 9. This known disc brake is, as already mentioned, disclosed in WO 2016 / 202778 A1, to which express reference is made.

[0038] In the Fig. 2 und 3 is shown a part of a disc brake in which, according to the invention, two V-shaped spreading elements 6 are provided, which are supported in the connecting region 13 of their respective spring legs 7 on the underside of the pad retaining bracket 11. The spring legs 7 of each spreading element 6 are held with their ends 15 on the opposite brake pads 3, wherein in the example according to the Figuren 2 and 3 the ends 15 which are angled relative to the spring legs 7 are inserted into holes in the lining carrier plate 4.

[0039] In the Fig. 3 It can be seen that a support 14 of a spring leg 7 of the respective expansion element 6, which support is curved outwards with respect to a brake disc 12, rests on the pad retaining spring 10 of the associated brake pad 3, whereby a tipping of the expansion element 6 is prevented.

[0040] In the Fig. 4-8 The assembly of brake pads 3, expansion elements 6 and brake disc 12 is shown in isolation, i.e. without brake calliper 1 and pad retaining bracket 11. Thus, the configuration of the expansion elements 6 can be clearly seen.

[0041] The Fig. 4 shows the design of the expansion elements 6 according to the Fig. 3 . In contrast, however, it is not attached directly to the pad carrier plate 4, but in holes in the pad retaining springs 10.

[0042] It is clearly visible that in the Fig. 4 In the example shown, the respective support 14 is formed only on one side and rests on the associated pad retaining spring 10, wherein the supports 14 of the two spreading elements 6 rest on the pad retaining springs 10 of the opposing brake pads 3.

[0043] The two expansion elements 6 are each designed asymmetrically with respect to an imaginary longitudinal axis X passing through the apex of the connecting region 13, in such a way that the two connecting regions 13 of the expansion elements 6 are positioned offset from one another in the assembled position, with the longitudinal axes X spaced from one another.

[0044] In the Fig. 5 In the example shown, the ends 15 of the spring legs 7 are also inserted into bores of the pad retaining springs 10. In this embodiment, each spring leg 7 has a support 14 that rests against the associated pad retaining spring 10.

[0045] One of the Fig. 4 A comparable design of the expansion elements 6 is shown in the Fig. 6 shown, ie with only one support 14 each. However, the ends 15 of the spring legs 7 are inserted into holes in the lining carrier plate 4.

[0046] In the Fig. 7 In the embodiment shown, the ends 15 of the spring legs 7 are inserted into eyelets 16 formed on the end of the respective pad retaining spring 10 and are held therein in a rotationally secure manner, so that a support 14 can be dispensed with.

[0047] In the Fig. 8 Another variant of the connection of the spring legs 7 to the lining carrier plates 4 can be seen. Here, the ends 15 are wound in such a way that a loop is formed, which is guided above the lining retaining springs 10 through tabs 17 formed on the respective lining carrier plate, which pass through the lining retaining springs 10. These ends 15 also serve to radially secure the lining retaining spring 10 relative to the lining carrier plate 4.

[0048] The expansion elements 6 as a detail are shown in the Fig. 9 , wherein in this embodiment, the supports 14 are formed on one side, ie, on one of the two spring legs 7. The ends 15 are formed at right angles to the spring legs 7.

[0049] The Fig. 10 shows an alternative design for mounting the expansion elements 6 on the pad retaining bracket 11. The connecting areas 13 rest on the pad retaining bracket 11 and are secured there by a clamping device 19, whereby the expansion elements 6 are preloaded in the radial direction for their defined positioning and to prevent noise caused by vibrations. The clamping device 19 is preferably mounted so that it can be moved axially, so that saddle movements are compensated for wear.

[0050] The ends 15 of the spring legs 7 are guided through elongated holes 20 of the lining carrier plates 4, wherein the ends 15 are angled at a right angle in the plane of the spring legs 7.

[0051] In the Fig. 11In the further exemplary embodiment shown, the two expansion elements 6 lie against one another with their connecting regions 13 and are connected to one another by a clamp 18, the expansion elements 6 not being asymmetrical but symmetrical in relation to the previously described longitudinal axis X.

[0052] An embodiment 1 comprises a disc brake for a commercial vehicle, with a brake calliper (1) designed as a sliding calliper and overlapping a brake disc (12), two brake pads (3) arranged therein, movable in opposite directions in the direction of the brake disc (12), each having a pad carrier plate (4) and a friction pad (5) fastened thereon, which are each arranged under pretension by means of a pad retaining spring (10), on which a pad retaining bracket (11) held on the brake calliper (1) and spanning a mounting opening of the brake calliper (1) is supported, in a pad shaft of a vehicle-side brake carrier (2) delimited by brake carrier horns (9) in the direction of rotation of the brake disc (12), and with a return device with which the brake pads (3) can be returned after a braking-induced displacement and release of the brake, wherein the return device engages the opposing brake pads (3),has resilient spreading elements (6) acting in the same way against the respective application direction, characterized in that two V-shaped spreading elements (6) are provided, which are supported or fastened to the pad retaining bracket (11) in the connecting region (13) of their respective spring legs (7), the spring legs (7) of each spreading element (6) being held by their ends (15) on the opposite brake pads (3).

[0053] An embodiment 2 comprises a disc brake according to embodiment 1, characterized in that at least one spring leg (7) has an outwardly shaped support (14) which rests on the associated brake pad (3).

[0054] An embodiment 3 comprises a disc brake according to embodiment 1 or 2, characterized in that each expansion element (6) is designed asymmetrically with respect to a longitudinal axis (X) guided through the apex of the connecting region (13).

[0055] An embodiment 4 comprises a disc brake according to one of the preceding embodiments, characterized in that the connecting regions (13) of the two spreading elements (6) are arranged offset from one another with respect to their longitudinal axes (X).

[0056] An embodiment 5 comprises a disc brake according to one of the preceding embodiments, characterized in that the spreading elements (6) are formed in one piece from a wire, preferably a spring wire.

[0057] An embodiment 6 comprises a disc brake according to one of the preceding embodiments, characterized in that each end (15) of the spring legs (7) is angled to the course of the adjacent region of the spring leg (7).

[0058] An embodiment 7 comprises a disc brake according to one of the preceding embodiments, characterized in that each end (15) is inserted into a bore of the pad retaining spring (10).

[0059] An embodiment 8 comprises a disc brake according to one of the preceding embodiments, characterized in that each end (15) of the spring leg (7) is inserted into a bore of the pad carrier plate (4).

[0060] An embodiment 9 comprises a disc brake according to one of the preceding embodiments, characterized in that the end (15) of the respective spring leg (7) is inserted into a bore of a tab (17) of the pad carrier plate (4), which passes through an elongated hole of the pad retaining spring (10).

[0061] An embodiment 10 comprises a disc brake according to one of the preceding embodiments, characterized in that the end (15) of the respective spring leg (7) is inserted into a molded eyelet (16) of the pad retaining spring (10).

[0062] An embodiment 11 comprises a disc brake according to one of the preceding embodiments, characterized in that the end (15) of each spring leg (7) is bent in a loop-shaped manner and is inserted into a bore of the tab (17).

[0063] An embodiment 12 comprises a disc brake according to one of the preceding embodiments, characterized in that the connecting regions (13) of the two spreading elements (6) lie against one another.

[0064] An embodiment 13 comprises a disc brake according to one of the preceding embodiments, characterized in that the adjacent connecting regions (13) are connected to one another, preferably by a clamp (18).

[0065] An embodiment 14 comprises a disc brake according to one of the preceding embodiments, characterized in that the spreading elements (6) are mirror-symmetrical with respect to the imaginary longitudinal axis (X).

[0066] An embodiment 15 comprises a disc brake according to one of the preceding embodiments, characterized in that the spreading elements (6) are fastened with their connecting regions (13) to the pad retaining bracket (11).

[0067] An embodiment 16 comprises a disc brake according to one of the preceding embodiments, characterized in that the connecting regions (13) rest on the pad retaining bracket (11).

[0068] An embodiment 17 comprises a disc brake according to one of the preceding embodiments, characterized in that the connecting regions (13) resting on the pad retaining bracket (11) are fastened to the pad retaining bracket (11) by means of a clamping device (19). List of reference symbols

[0069] 1 Brake calliper 2 Brake carrier 3 Brake pad 4 Pad carrier plate 5 Friction lining 6 Expanding element 7 Spring leg 8 Retaining bracket 9 Brake carrier horn 10 Pad retaining spring 11 Pad retaining bracket 12 Brake disc 13 Connection area 14 Support 15 End 16 Eyelet 17 Tab 20 18 Clip 19 Clamping device 20 Slotted hole

Claims

1. Disc brake for a commercial vehicle, comprising a brake calliper (1) designed as a sliding calliper and spanning a brake disc (12), two brake pads (3) arranged therein, movable in opposite directions in the direction of the brake disc (12), each having a pad carrier plate (4) and a friction pad (5) fastened thereon, which brake pads (3) are each arranged under pretension by means of a pad retaining spring (10), on which a pad retaining bracket (11) held on the brake calliper (1) and spanning a mounting opening of the brake calliper (1) is supported, in a pad shaft of a vehicle-side brake carrier (2) delimited by brake carrier horns (9) in the direction of rotation of the brake disc (12), and a return device with which the brake pads (3) can be returned after a braking-induced displacement and release of the brake, wherein the return device engages the opposing brake pads (3),has resilient spreading elements (6) acting in the same way against the respective application direction, wherein two V-shaped spreading elements (6) are provided, which are supported or fastened to the pad retaining bracket (11) in the connecting region (13) of their respective spring legs (7), wherein the spring legs (7) of each spreading element (6) are held by their ends (15) on the opposite brake pads (3), , characterized in that each end (15) is inserted into a hole in the pad retaining spring (10) or into a hole in the pad carrier plate (4).

2. Disc brake according to claim 1, characterized in that at least one spring leg (7) has an outwardly shaped support (14) which rests on the associated brake pad (3).

3. Disc brake according to claim 1 or 2, characterized in that each expansion element (6) is designed asymmetrically with respect to a longitudinal axis (X) passing through the apex of the connecting region (13).

4. Disc brake according to one of the preceding claims, characterized in that the connecting regions (13) of the two expansion elements (6) are arranged offset from one another with respect to their longitudinal axes (X).

5. Disc brake according to one of the preceding claims, characterized in that the spreading elements (6) are formed in one piece from a wire, preferably a spring wire.

6. Disc brake according to one of the preceding claims, characterized in that each end (15) of the spring leg (7) is angled to the course of the adjacent region of the spring leg (7).

7. Disc brake according to one of the preceding claims, characterized in that the connecting areas (13) of the two spreading elements (6) lie against each other.

8. Disc brake according to one of the preceding claims, characterized in that the adjacent connecting areas (13) are connected to one another, preferably by a clamp (18).

9. Disc brake according to one of the preceding claims, characterized in that the spreading elements (6) are mirror-symmetrical with respect to the imaginary longitudinal axis (X).

10. Disc brake according to one of the preceding claims, characterized in that the spreading elements (6) with their connecting areas (13) are fastened to the pad retaining bracket (11).

11. Disc brake according to one of the preceding claims, characterized in that the connecting areas (13) rest on the pad retaining bracket (11).

12. Disc brake according to one of the preceding claims, characterized in that the connecting areas (13) resting on the pad retaining bracket (11) are fastened to the pad retaining bracket (11) by means of a clamping device (19).

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